Is a UK terrorist attack 'inevitable'?

The head of Europol, the EU's law enforcement agency, has said that 5000 people are suspected to have been radicalised in Europe. Andrew Dorman, professor of international security at King's College London, and Maajid Nawaz, founding chairman of the counter extremism think tank the Quilliam Foundation, discuss the likelihood of a Brussels-style terrorist attack occurring in the UK. (Image: London commuters. Credit: BBC)